Get back to MacOS. While your Mac is restarting, hold the "Option" key and select the Hard drive where MacOS is installed.

Undo what Boot Camp has done.

To do this, you will need to open Boot Camp assistant again and "Restore to a Single Volume"

Restart your Mac and start the process again, make sure you maintain the changes on Step 1.

And that should be it. That's what it took for me to resolve this issue. Let me know in the comments if this worked for you, if you found a different solution, let me know, so I can add it to the article.